Table 4.

Equilibrium Constants in D₂O for Addition of Glycine to Carbonyl Compounds, and Second-Order Rate Constants k_DO for Carbon Deprotonation of the Imine or Iminium Ion Adduct.^a

Aldehyde	Carbon Acid	Kaddb (M−1)	(Kadd)+c (M−1)	kDOd (M−1 s−1)
		3.5 × 10−2	5.6 × 10−3	4.2
		44e	0.0033e	2.90 × 10−4
		1.76e	72e	0.19

^aAt 25 °C and I = 1.0 (KCl).

^bEquilibrium constant for addition of the basic amino form of glycine to the carbonyl compound.

^cEquilibrium constant for addition of glycine zwitterion to the carbonyl compound.

^dSecond-order rate constant for carbon deprotonation of the iminium ion adduct by deuterioxide ion in D₂O.

^eData from ref 36.